Which pitch EFCS mode is considered primary during most phases of flight?

During most phases of flight, the pitch rate command/attitude hold mode is considered the primary mode of the Envelope Flight Control System (EFCS). This is due to its ability to maintain the desired pitch attitude while allowing for quick response to changes in pitch rate. This mode provides the pilot with a controlled and stable flight experience, ensuring that the aircraft can adjust its pitch effectively to maintain the desired flight path.

In this mode, the system manages the aircraft's pitch by commanding the control surfaces to adjust based on the difference between the pilot's inputs and the actual pitch rate, thereby enhancing responsiveness. This adaptability is crucial during various phases of flight, such as takeoff, cruise, and landing, where maintaining pitch stability and control is vital for safety and performance.

Other modes serve specialized functions but do not provide the same level of responsiveness or stability that pitch rate command/attitude hold offers in these critical flight phases. This is why it is designated as the primary mode during most operations.